Sources in Israel’s security establishment say the chemical-weapons assault in Syria that killed more than 70 people Tuesday was approved by the highest levels of Syrian President Bashar al-Assad’s regime in order to send rebel groups a threatening message, Haaretz reports. Mostly civilians, including 20 children, died from the lethal gas. The attack, most sources allege, was carried out by Syrian government forces onto a rebel-held area in the northern Idlib province. It is still unclear if Russian or Iranian figures were involved in the plan. Syria has denied involvement, despite witness accounts that point to the government as the perpetrator.